Slow 5Ghz speed.

I got a nice shiny Hub One and everything is fine apart from transfers over the 5Ghz network.

I can't get anymore than around 14MB/s (120Mbps ish?) which is way below what it should be capable of.

I have confirmed it is using 5Ghz as I disabled 2.4Ghz just to be sure, I also made sure no other access points in the area, I checked its set at the highest rate (1300Mbps) and the card in the machine is capable of 867Mbps. (Network status on the machine shows it is actually connected at 867Mbps)

Copying from one machine to another seems to produce a slow rate, one machine is on the gigabit wired and confirmed to be running at gigabit as I get at least 100MB/s if I use wire to both machines.

The only thing I have noticed when I am copying is there is a very high pitched squeal coming from the router which goes after the transfer completes, is it broken and need replacing already ?

* Card is internal to laptop: Intel Dual Band Wireless-AC 7260 Rated upto 867Mbps... (it connects at 867Mbps and I can sit infront of the router or about 2m away and still retain that, so not a range issue.)